ISTANBUL (AP) — Turkish labor groups fanned a wave of defiance against Prime Minister Recep Tayyip Erdogan’s authority, leading rallies and a one-day strike to support activists whose two-week standoff with the government has shaken the country’s secular democracy.

Riot police again deployed in Turkey’s two main cities, and authorities kept up their unyielding stance against the street demonstrations centering on Istanbul’s Taksim Square. But Monday’s police sweep was less forceful than in recent days, with only scattered firing of tear gas and water cannon on pockets of protesters.

After activists were ousted from their sit-in in adjacent Gezi Park over the weekend, two labor confederations that represent some 330,000 workers picked up the slack Monday by calling a strike and demonstrations nationwide. Unionists turned up by the thousands in Ankara, Istanbul, coastal Izmir and elsewhere.

The turnout defied Turkey’s interior minister, Muammer Guler, who warned that anyone taking part in unlawful demonstrations would “bear the legal consequences.” But one analyst called the rallies a “legitimate and a lawful expression of constitutional rights.”

“People are raising their voices against the excessive use of police force,” said Koray Caliskan, a political science professor at Istanbul’s Bosphorus University. Demonstrators, he said, were showing they were no longer cowed by authorities, and “the fear threshold has been broken.”

In a sign that authorities were increasingly impatient, Deputy Prime Minister Bulent Arinc floated the prospect that authorities could call in troops to quash the protests.

Erdogan’s opponents have grown increasingly suspicious about what they call a gradual erosion of freedoms and secular values under his Islamic-rooted ruling party. It has passed new curbs on alcohol and tried, but later abandoned its plans, to limit women’s access to abortion.

The government set off protests nationwide and drew criticism abroad over a police crackdown that began May 31 against environmentalists and other activists in Taksim Square who were protesting against plans to tear down trees and re-develop Gezi Park. Thousands have flooded the streets nightly since then, many honking car horns and waving Turkish flags.

Erdogan, who has held power for 10 years and was re-elected in 2011, mobilized his supporters over the weekend in two huge rallies — insisting his duty was to keep order, railing against media coverage of the protests and lashing out at unspecified foreigners whom he said want to hurt Turkey.

TV images Monday showed crowds of government supporters in Istanbul facing down some protesters and chanting “the hands targeting the police should be broken.” On Twitter, a trending topic urged protesters to stay home — some expressing concern that pro-government mobs might attack them.

But overnight, for hours, a lone man stood silently on Taksim Square, eventually joined by about 20 other people who did likewise before police escorted them away. The group put up no resistance. Pockets of unrest erupted elsewhere in Istanbul, with police resorting to water cannon and tear gas at times.

The labor rallies had a more structured feel than the counterculture-style sit-in at Gezi Park’s tent city, and the work stoppage involved many professionals who make up a liberal, urban class that mostly backs the anti-Erdogan protesters. But labor strikes often have little visible impact on daily life in Turkey, a country of about 75 million, and Monday’s rallies were no different.

Feride Aksu Tanik, of the Turkish Doctors Union, said it had called its work stoppage “to protest against the police force that attacks children, youngsters and everyone violently, and to the detentions of doctors who provide voluntary services to the injured.”

Turkey’s doctors association said Monday that four people, including a police officer, had died in violence linked to the crackdown, and an investigation was ongoing into the death of a fifth person who was exposed to tear gas. More than 7,800 people have been injured; six remained in critical condition and 11 people lost their eyesight.

The tough tactics used by the government to disperse protesters during the past two weeks have drawn international criticism.

Chancellor Angela Merkel of Germany — home to some 3 million Turks — told German broadcaster RTL she was “appalled” to see footage of police forces moving in to clear Gezi Park over the weekend. She criticized the crackdown by Turkish police as “much too strong.”